Cancer immunotherapy has been in the dark for a long time, as good results were obtained in mouse models and basic in vitro studies, but no efficacy was observed in clinical trials. However, immune checkpoint inhibitors (ICIs), a new class of drugs that remove the immunosuppressive mechanism, have had a strong impact on cancer treatment by demonstrating long-term therapeutic effects in clinical practice. As a result, ICIs have shown efficacy in various types of carcinomas and are now widely used in daily clinical practice. While a new future in cancer immunotherapy is opening up, there are patients who show resistance after initial response to ICI treatment or who are completely ineffective, making the search for biomarkers for ICI treatment an urgent issue in clinical practice. We have been conducting blood cell and serum analyses using pre- and post-treatment blood samples of ICI-treated patients. In this meeting, we will report the results of those analyses. We have also been conducting analytical studies using the findings from clinical samples and incorporating them into basic research, and the results of these analyses will also be presented. Cancer immunotherapy has now bridged the gap from basic research to clinical practice, and is now in an era in which further basic analytical research is conducted based on clinical data, and research that develops into clinical practice and leads to the future has become the mainstream.
